@@ -53,11 +53,15 @@ The Alya System is a Computational Mechanics code capable of solving different p

# Code_Saturne <a name="saturne"></a>

Code_Saturne® is a multipurpose Computational Fluid Dynamics (CFD) software package, which has been developed by EDF (France) since 1997. The code was originally designed for industrial applications and research activities in several fields related to energy production; typical examples include nuclear power thermal-hydraulics, gas and coal combustion, turbo-machinery, heating, ventilation, and air conditioning. In 2007, EDF released the code as open-source and this provides both industry and academia to benefit from its extensive pedigree. Code_Saturne®’s open-source status allows for answers to specific needs that cannot easily be made available in commercial “black box” packages. It also makes it possible for industrial users and for their subcontractors to develop and maintain their own independent expertise and to fully control the software they use.

Code_Saturne is open-source multi-purpose CFD software, primarily developed by EDF R&D and maintained by them. It relies on the Finite Volume method and a collocated arrangement of unknowns to solve the Navier-Stokes equations, for incompressible or compressible flows, laminar or turbulent flows and non-Newtonian and Newtonian fluids. A highly parallel coupling library (Parallel Locator Exchange - PLE) is also available in the distribution to account for other physics, such as conjugate heat transfer and structure mechanics. For the incompressible solver, the pressure is solved using an integrated Algebraic Multi-Grid algorithm and the scalars are computed by conjugate gradient methods or Gauss-Seidel/Jacobi.

Code_Saturne® is based on a co-located finite volume approach that can handle three-dimensional meshes built with any type of cell (tetrahedral, hexahedral, prismatic, pyramidal, polyhedral) and with any type of grid structure (unstructured, block structured, hybrid). The code is able to simulate either incompressible or compressible flows, with or without heat transfer, and has a variety of models to account for turbulence. Dedicated modules are available for specific physics such as radiative heat transfer, combustion (e.g. with gas, coal and heavy fuel oil), magneto-hydro dynamics, and compressible flows, two-phase flows. The software comprises of around 350 000 lines of source code, with about 37% written in Fortran90, 50% in C and 15% in Python. The code is parallelised using MPI with some OpenMP.

The original version of the code is written in C for pre-postprocessing, IO handling, parallelisation handling, linear solvers and gradient computation, and Fortran 95 for most of the physics implementation. MPI is used on distributed memory machines and OpenMP pragmas have been added to the most costly parts of the code to handle potential shared memory. The version used in this work (also freely available) relies also on CUDA to take advantage of potential GPU acceleration.

- Web site: http://code-saturne.org

The equations are solved iteratively using time-marching algorithms, and most of the time spent during a time step is usually due to the computation of the velocity-pressure coupling, for simple physics. For this reason, the two test cases chosen for the benchmark suite have been designed to assess the velocity-pressure coupling computation, and rely on the same configuration, with a mesh 8 times larger for Test Case B than for Test Case A, the time step being halved to ensure a correct Courant number.

- Web site: https://code-saturne.org

- Code download:

- Code download: http://code-saturne.org/cms/download or https://repository.prace-ri.eu/ueabs/Code_Saturne/1.3/Code_Saturne-4.0.6_UEABS.tar.gz

- Disclaimer: please note that by downloading the code from this website, you agree to be bound by the terms of the GPL license.

@@ -67,7 +71,7 @@ Code_Saturne® is based on a co-located finite volume approach that can hand

# CP2K <a name="cp2k"></a>

CP2K is a freely available quantum chemistry and solid-state physics software package that can perform atomistic simulations of solid state, liquid, molecular, periodic, material, crystal, and biological systems. CP2K provides a general framework for different modelling methods such as DFT using the mixed Gaussian and plane waves approaches GPW and GAPW. Supported theory levels include DFTB, LDA, GGA, MP2, RPA, semi-empirical methods (AM1, PM3, PM6, RM1, MNDO, ...), and classical force fields (AMBER, CHARMM, ...). CP2K can do simulations of molecular dynamics, metadynamics, Monte Carlo, Ehrenfest dynamics, vibrational analysis, core level spectroscopy, energy minimisation, and transition state optimisation using NEB or dimer method.

CP2K is a freely available quantum chemistry and solid-state physics software package that can perform atomistic simulations of solid state, liquid, molecular, periodic, material, crystal, and biological systems. CP2K provides a general framework for different modelling methods such as DFT using the mixed Gaussian and plane waves approaches GPW and GAPW. Supported theory levels include DFTB, LDA, GGA, MP2, RPA, semi-empirical methods (AM1, PM3, PM6, RM1, MNDO, ...), and classical force fields (AMBER, CHARMM, ...). CP2K can do simulations of molecular dynamics, metadynamics, Monte Carlo, Ehrenfest dynamics, vibrational analysis, core level spectroscopy, energy minimisation, and transition state optimisation using NEB or dimer method.

CP2K is written in Fortran 2008 and can be run in parallel using a combination of multi-threading, MPI, and CUDA. All of CP2K is MPI parallelised, with some additional loops also being OpenMP parallelised. It is therefore most important to take advantage of MPI parallelisation, however running one MPI rank per CPU core often leads to memory shortage. At this point OpenMP threads can be used to utilise all CPU cores without suffering an overly large memory footprint. The optimal ratio between MPI ranks and OpenMP threads depends on the type of simulation and the system in question. CP2K supports CUDA, allowing it to offload some linear algebra operations including sparse matrix multiplications to the GPU through its DBCSR acceleration layer. FFTs can optionally also be offloaded to the GPU. Benefits of GPU offloading may yield improved performance depending on the type of simulation and the system in question.